Invest.java

import java.io.*;
class Invest
{
   public static void main(String args[])
  {   
      Float principalAmount=new Float(0);        //Converting number to object
      Float interestRate=new Float(0);
      int numYears=0;

      try
      {
        DataInputStream in=new DataInputStream(System.in);

        System.out.print("Enter Principal Amount : ");
        System.out.flush( );
        String principalString=in.readLine( );
        principalAmount=Float.valueOf(principalString);    //String object to number object
        
        System.out.print("Enter Interest Rate : ");
        System.out.flush( );
        String interestString=in.readLine( );
        interestRate=Float.valueOf(interestString);

        System.out.print("Enter Number of Years : ");
        System.out.flush( );
        String yearsString=in.readLine( );
        numYears=Integer.parseInt(yearsString);           //Numeric strings to numbers 
      }
      catch(IOException e)
      {
        System.out.println("I/O Error");
        System.exit(1);
      }
      float value=loan(principalAmount.floatValue( ),interestRate.floatValue( ),numYears);
      printline( );
      System.out.println("Final Value = " +value);
      printline( );
  }    
   
     //Method to compute Final Value

      static float loan(float p,float r,int n)
     {
       int year=1;
       float sum=p;
       while (year <= n)
      {
        sum=sum*(1+r);
        year=year+1;
      }
      return sum;
     }

    //Method to draw a line

      static void printline( )
     {
       for(int i=1;i<=30;i++)
       {
         System.out.print("=");
       }
       System.out.println("  ");
     }
}